Systems and methods for depositing low-k dielectric films

ABSTRACT

Exemplary methods of forming a silicon-and-carbon-containing material may include flowing a silicon-oxygen-and-carbon-containing precursor into a processing region of a semiconductor processing chamber. A substrate may be housed within the processing region of the semiconductor processing chamber. The methods may include forming a plasma within the processing region of the silicon-and-carbon-containing precursor. The plasma may be formed at a frequency less than 15 MHz (e.g., 13.56 MHz). The methods may include depositing a silicon-and-carbon-containing material on the substrate. The silicon-and-carbon-containing material as-deposited may be characterized by a dielectric constant below or about 3.5 and a hardness greater than about 3 Gpa.

TECHNICAL FIELD

The present technology relates to deposition processes and chambers.More specifically, the present technology relates to methods ofproducing low-k films that may not utilize UV treatments.

BACKGROUND

Integrated circuits are made possible by processes which produceintricately patterned material layers on substrate surfaces. Producingpatterned material on a substrate requires controlled methods forforming and removing material. Material characteristics may affect howthe device operates, and may also affect how the films are removedrelative to one another. Plasma-enhanced deposition may produce filmshaving certain characteristics. Many films that are formed requireadditional processing to adjust or enhance the material characteristicsof the film in order to provide suitable properties.

Thus, there is a need for improved systems and methods that can be usedto produce high quality devices and structures. These and other needsare addressed by the present technology.

SUMMARY

Exemplary methods of forming a silicon-oxygen-and-carbon-containingmaterial may include flowing a silicon-oxygen-and-carbon-containingprecursor into a processing region of a semiconductor processingchamber. A substrate may be housed within the processing region of thesemiconductor processing chamber. The methods may include forming aplasma within the processing region of thesilicon-oxygen-and-carbon-containing precursor. The plasma may be formedat a frequency below 15 MHz (e.g., 13.56 MHz). The methods may includedepositing a silicon-oxygen-and-carbon-containing material on thesubstrate. The silicon-oxygen-and-carbon-containing materialas-deposited may be characterized by a dielectric constant ranging from3.0 to 3.3, and a hardness ranging from 3.5 GPa to 6.0 GPa.

In some embodiments, the silicon-oxygen-and-carbon-containing precursormay include oxygen. The silicon-and-carbon-containing precursor may becharacterized by a carbon-to-silicon ratio greater than 1. The plasmamay be formed at a frequency below 15 MHz. Thesilicon-oxygen-and-carbon-containing material as-deposited may becharacterized by a dielectric constant below 3.5 (e.g., 3.0 to 3.3). Thesilicon-and-carbon-containing material as-deposited may be characterizedby a hardness of greater than or about 3.5 Gpa. Thesilicon-and-carbon-containing material as-deposited may be characterizedby a Young's modulus of greater than or about 5 Gpa. Thesilicon-and-carbon-containing material as-deposited may be characterizedby a methyl incorporation less than or about 3% (e.g., 1.5% to 2.25%).The silicon-and-carbon-containing material as-deposited may becharacterized by a percentage of Si—C—Si bonds, relative to the totalsilicon bonds, as ranging from 0.15% to 0.3%.

Some embodiments of the present technology may encompass methods offorming a silicon-and-carbon-containing material. The methods mayinclude providing a deposition precursor into a processing region of asemiconductor processing chamber, wherein a substrate is housed withinthe processing region of the semiconductor processing chamber, andwherein the deposition precursor is characterized by Formula 1:

wherein in Formula 1,R¹ may include a C₁-C₆ alkyl group, such as —CH₃, —CH₂CH₃, —CH₂CH₂CH₃,—CH₂CH₂CH₂CH₃, —CH₂CH₂CH₂CH₂CH₃, or —CH₂CH₂CH₂CH₂CH₂CH₃,R² may include a C₁-C₆ alkyl group, such as —CH₃, —CH₂CH₃, —CH₂CH₂CH₃,—CH₂CH₂CH₂CH₃, —CH₂CH₂CH₂CH₂CH₃, or —CH₂CH₂CH₂CH₂CH₂CH₃,R³ may include —OCH₃, —CH₃, —H, —(CH₂)_(n)CH₃, —O(CH₂)_(n)CH₃, —CH═CH₂,—CH₂—CH₂—(CH₂CH₃)₂, or —CH₂—CH(CH₃)₂, andR⁴ may include —OCH₃, —CH₃, —H, —(CH₂)_(n)CH₃, —O(CH₂)_(n)CH₃, —CH═CH₂,—CH₂—CH₂—(CH₂CH₃)₂, or —CH₂—CH(CH₃)₂.The method may include forming a plasma within the processing region ofthe deposition precursor. The plasma may be formed at a frequency below15 MHz. The methods may include depositing asilicon-and-carbon-containing material on the substrate. Thesilicon-and-carbon-containing material as-deposited may be characterizedby a dielectric constant below 3.5 and a hardness ranging from 3.5 GPato 6.0 GPa.

In some embodiments, the deposition precursor may be characterized byratio of carbon to silicon of greater than or about 3. The depositionprecursor may be characterized by ratio of oxygen to silicon of greaterthan or about 1.5. The silicon-and-carbon-containing materialas-deposited may be characterized by a dielectric constant below orabout 3.5. The silicon-and-carbon-containing material as-deposited maybe characterized by a hardness of greater than or about 3 Gpa. Thesilicon-and-carbon-containing material as-deposited may be characterizedby a Young's modulus of greater than or about 5 Gpa. Thesilicon-and-carbon-containing material as-deposited may be characterizedby a methyl incorporation less than or about 3%. Thesilicon-and-carbon-containing material as-deposited may be characterizedby a percentage of Si—C—Si bonds, relative to the total silicon bonds,as ranging from 0.15% to 0.3%.

Some embodiments of the present technology may encompass methods offorming a silicon-and-carbon-containing material. The methods mayinclude flowing a silicon-and-carbon-and-oxygen-containing precursorinto a processing region of a semiconductor processing chamber. Asubstrate may be housed within the processing region of thesemiconductor processing chamber. The methods may include forming aplasma within the processing region of thesilicon-and-carbon-and-oxygen-containing precursor. The plasma may beformed at a frequency below 15 MHz. The methods may include depositing asilicon-and-carbon-containing material on the substrate. Thesilicon-and-carbon-containing material as-deposited may be characterizedby a dielectric constant below 3.5.

In some embodiments, the silicon-and-carbon-containing materialas-deposited is characterized by a hardness of greater than or about 3Gpa. The silicon-and-carbon-containing material as-deposited may becharacterized by a Young's modulus of greater than or about 5 Gpa. Thesilicon-and-carbon-containing material as-deposited may be characterizedby a methyl incorporation less than or about 3%. Thesilicon-and-carbon-containing material as-deposited may be characterizedby a percentage of Si—C—Si bonds, relative to the total silicon bonds,as ranging from 0.15% to 0.3%.

Such technology may provide numerous benefits over conventional systemsand techniques. For example, utilizing higher frequency power mayimprove deposition characteristics. Additionally, reducing the low-kformation to a single-chamber process may reduce production costs, costof ownership, and production queue times. These and other embodiments,along with many of their advantages and features, are described in moredetail in conjunction with the below description and attached figures.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the disclosedtechnology may be realized by reference to the remaining portions of thespecification and the drawings.

FIG. 1 shows a top plan view of an exemplary processing system accordingto some embodiments of the present technology.

FIG. 2 shows a schematic cross-sectional view of an exemplary plasmasystem according to some embodiments of the present technology.

FIG. 3 shows operations of an exemplary method of semiconductorprocessing according to some embodiments of the present technology.

Several of the figures are included as schematics. It is to beunderstood that the figures are for illustrative purposes, and are notto be considered of scale unless specifically stated to be of scale.Additionally, as schematics, the figures are provided to aidcomprehension and may not include all aspects or information compared torealistic representations, and may include exaggerated material forillustrative purposes.

In the appended figures, similar components and/or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a letter thatdistinguishes among the similar components. If only the first referencelabel is used in the specification, the description is applicable to anyone of the similar components having the same first reference labelirrespective of the letter.

DETAILED DESCRIPTION

During back-end-of-line semiconductor processing, structures may beproduced to facilitate metallization, such as dual-damascene structures.These structures may be produced with several processing steps utilizingmasking and low-k films, which may be processed and removed. The removalmay be performed with chemical-mechanical processes which include anamount of physical abrasion of the materials for removal. Low-k filmsmay be characterized by relatively lower hardness and tensile modulus,which may cause limit their effectiveness during polishing, as the highsheer stresses during polishing may crack low-k films and lead to devicefailure. To improve hardness while maintaining lower k values, manyconventional technologies are forced to include additional processingsteps like UV curing to improve hardness of the films. These additionalprocesses may greatly reduce throughput and often require additionalprocessing chambers on the tool.

The present technology may overcome these issues be providing low-kfilms that, as deposited, may be characterized by higher hardness. Byperforming deposition at higher temperature with particular precursorscharacterized by particular oxygen-to-carbon ratios may increasesilicon-and-oxide bonding within the film, while maintaining requiredratios of carbon moieties to maintain reduced dielectric constant. Thismay overcome the natural tendency of dielectric constant to rise withmodulus and hardness, while also reducing the number of operationsrequired during processing. In particular, the present technology maynot utilize subsequent processing after deposition, including UVexposure, plasma treatment, or other processing operations to post-treatthe film to improve hardness.

Although the remaining disclosure will routinely identify specificdeposition processes utilizing the disclosed technology, it will bereadily understood that the systems and methods are equally applicableto other deposition and cleaning chambers, as well as processes as mayoccur in the described chambers. Accordingly, the technology should notbe considered to be so limited as for use with these specific depositionprocesses or chambers alone. The disclosure will discuss one possiblesystem and chamber that may be used to perform deposition processesaccording to embodiments of the present technology before additionaldetails according to embodiments of the present technology aredescribed.

FIG. 1 shows a top plan view of one embodiment of a processing system100 of deposition, etching, baking, and curing chambers according toembodiments. In the figure, a pair of front opening unified pods 102supply substrates of a variety of sizes that are received by roboticarms 104 and placed into a low pressure holding area 106 before beingplaced into one of the substrate processing chambers 108 a-f, positionedin tandem sections 109 a-c. A second robotic arm 110 may be used totransport the substrate wafers from the holding area 106 to thesubstrate processing chambers 108 a-f and back. Each substrateprocessing chamber 108 a-f, can be outfitted to perform a number ofsubstrate processing operations including formation of stacks ofsemiconductor materials described herein in addition to plasma-enhancedchemical vapor deposition, atomic layer deposition, physical vapordeposition, etch, pre-clean, degas, orientation, and other substrateprocesses including, annealing, ashing, etc.

The substrate processing chambers 108 a-f may include one or more systemcomponents for depositing, annealing, curing and/or etching a dielectricor other film on the substrate. In one configuration, two pairs of theprocessing chambers, e.g., 108 c-d and 108 e-f, may be used to depositdielectric material on the substrate, and the third pair of processingchambers, e.g., 108 a-b, may be used to etch the deposited dielectric.In another configuration, all three pairs of chambers, e.g., 108 a-f,may be configured to deposit stacks of alternating dielectric films onthe substrate. Any one or more of the processes described may be carriedout in chambers separated from the fabrication system shown in differentembodiments. It will be appreciated that additional configurations ofdeposition, etching, annealing, and curing chambers for dielectric filmsare contemplated by system 100.

FIG. 2 shows a schematic cross-sectional view of an exemplary plasmasystem 200 according to some embodiments of the present technology.Plasma system 200 may illustrate a pair of processing chambers 108 thatmay be fitted in one or more of tandem sections 109 described above, andwhich may include lid stack components according to embodiments of thepresent technology, and as may be explained further below. The plasmasystem 200 generally may include a chamber body 202 having sidewalls212, a bottom wall 216, and an interior sidewall 201 defining a pair ofprocessing regions 220A and 220B. Each of the processing regions220A-220B may be similarly configured, and may include identicalcomponents.

For example, processing region 220B, the components of which may also beincluded in processing region 220A, may include a pedestal 228 disposedin the processing region through a passage 222 formed in the bottom wall216 in the plasma system 200. The pedestal 228 may provide a heateradapted to support a substrate 229 on an exposed surface of thepedestal, such as a body portion. The pedestal 228 may include heatingelements 232, for example resistive heating elements, which may heat andcontrol the substrate temperature at a desired process temperature.Pedestal 228 may also be heated by a remote heating element, such as alamp assembly, or any other heating device.

The body of pedestal 228 may be coupled by a flange 233 to a stem 226.The stem 226 may electrically couple the pedestal 228 with a poweroutlet or power box 203. The power box 203 may include a drive systemthat controls the elevation and movement of the pedestal 228 within theprocessing region 220B. The stem 226 may also include electrical powerinterfaces to provide electrical power to the pedestal 228. The powerbox 203 may also include interfaces for electrical power and temperatureindicators, such as a thermocouple interface. The stem 226 may include abase assembly 238 adapted to detachably couple with the power box 203. Acircumferential ring 235 is shown above the power box 203. In someembodiments, the circumferential ring 235 may be a shoulder adapted as amechanical stop or land configured to provide a mechanical interfacebetween the base assembly 238 and the upper surface of the power box203.

A rod 230 may be included through a passage 224 formed in the bottomwall 216 of the processing region 220B and may be utilized to positionsubstrate lift pins 261 disposed through the body of pedestal 228. Thesubstrate lift pins 261 may selectively space the substrate 229 from thepedestal to facilitate exchange of the substrate 229 with a robotutilized for transferring the substrate 229 into and out of theprocessing region 220B through a substrate transfer port 260.

A chamber lid 204 may be coupled with a top portion of the chamber body202. The lid 204 may accommodate one or more precursor distributionsystems 208 coupled thereto. The precursor distribution system 208 mayinclude a precursor inlet passage 240 which may deliver reactant andcleaning precursors through a dual-channel showerhead 218 into theprocessing region 220B. The dual-channel showerhead 218 may include anannular base plate 248 having a blocker plate 244 disposed intermediateto a faceplate 246. A radio frequency (“RF”) source 265 may be coupledwith the dual-channel showerhead 218, which may power the dual-channelshowerhead 218 to facilitate generating a plasma region between thefaceplate 246 of the dual-channel showerhead 218 and the pedestal 228.The dual-channel showerhead 218 and/or faceplate 246 may include one ormore openings to permit the flow of precursors from the precursordistribution system 208 to the processing regions 220A and/or 220B. Insome embodiments, the openings may include at least one ofstraight-shaped openings and conical-shaped openings. In someembodiments, the RF source may be coupled with other portions of thechamber body 202, such as the pedestal 228, to facilitate plasmageneration. A dielectric isolator 258 may be disposed between the lid204 and the dual-channel showerhead 218 to prevent conducting RF powerto the lid 204. A shadow ring 206 may be disposed on the periphery ofthe pedestal 228 that engages the pedestal 228.

An optional cooling channel 247 may be formed in the annular base plate248 of the precursor distribution system 208 to cool the annular baseplate 248 during operation. A heat transfer fluid, such as water,ethylene glycol, a gas, or the like, may be circulated through thecooling channel 247 such that the base plate 248 may be maintained at apredefined temperature. A liner assembly 227 may be disposed within theprocessing region 220B in close proximity to the sidewalls 201, 212 ofthe chamber body 202 to prevent exposure of the sidewalls 201, 212 tothe processing environment within the processing region 220B. The linerassembly 227 may include a circumferential pumping cavity 225, which maybe coupled to a pumping system 264 configured to exhaust gases andbyproducts from the processing region 220B and control the pressurewithin the processing region 220B. A plurality of exhaust ports 231 maybe formed on the liner assembly 227. The exhaust ports 231 may beconfigured to allow the flow of gases from the processing region 220B tothe circumferential pumping cavity 225 in a manner that promotesprocessing within the system 200.

FIG. 3 shows operations of an exemplary method 300 of semiconductorprocessing according to some embodiments of the present technology. Themethod may be performed in a variety of processing chambers, includingprocessing system 200 described above, as well as any other chamber inwhich plasma deposition may be performed. Method 300 may include anumber of optional operations, which may or may not be specificallyassociated with some embodiments of methods according to the presenttechnology.

Method 300 may include PECVD processing operations to form low-k,high-hardness, silicon-oxygen-and-carbon-containing materialsas-deposited on a substrate without the need for a post-depositiontreatment (e.g., UV curing) to achieve the low-k and high-hardnessproperties of the material. The method may include optional operationsprior to initiation of method 300, or the method may include additionaloperations after the deposition of the low-k, high-hardness material.Method 300, as shown in FIG. 3, may include flowing one or moreprecursors into a processing chamber at operation 305, which may deliverthe precursor or precursors into a processing region of the chamberwhere a substrate may be housed, such as region 220, for example.

In some embodiments, the precursor may be or include asilicon-oxygen-and-carbon-containing precursor for producing a low-k,high-hardness silicon-oxygen-and-carbon-containing material. Theprecursors may or may not include delivery of additional precursors,such as carrier gases and/or one or oxygen gas. In some embodiments, thedeposition precursor may utilize a singlesilicon-oxygen-and-carbon-containing deposition precursor. Although acarrier gas, such as an inert precursor, may be delivered with thedeposition precursor, additional precursors intended to react with thedeposition precursor and produce deposition products may not be used.Exemplary carrier gases may include at least one of helium and nitrogen(N₂).

Deposition precursors may include precursors having Si—O bonds and Si—Cbonds, and may include linear branched precursors, cyclic precursors, orany number of additional precursors. In some embodiments the precursorsmay be characterized by certain ratios of carbon and/or oxygen tosilicon. For example, in some embodiments a ratio of either carbon oroxygen to silicon may be greater than or about 1, and may be greaterthan or about 1.5, greater than or about 2, greater than or about 2.5,greater than or about 3, greater than or about 3.5, greater than orabout 4, or more. By increasing the amount of carbon or oxygen relativeto silicon, additional incorporation within the film of residualmoieties or molecules may be increased. This may improve materialproperties, as well as lower a dielectric constant as will be describedfurther below.

In a description of a specific embodiment above, thesilicon-oxygen-and-carbon-containing deposition precursor was specifiedas having a central silicon atom and at least one methyl group and atleast one methoxy group bonded to the central silicon. Specific examplesof these methyl-methoxy-siloxane precursors included DMDMOS, TMMOS, andMTMOS. The present technology contemplates the use of additionaldeposition precursors that may replace or complement the specificprecursor examples listed above. These additional precursors may includeat least on silicon atom, at least one silicon-and-alkyl group bond, andat least one silicon-and-alkoxy group bond. In some examples, such aswhere there is a single silicon atom, the alky group and the alkoxygroup are both bonded to the same silicon atom. In additional examples,at least one silicon atom has at least one silicon-and-alkyl groupbonds, and at least one other silicon atom has at least onesilicon-and-alkoxy group bond. The DMDMOS, TMMOS, and MTMOS precursorsdescribe above have methyl groups as the alkyl group, and methoxy groupsas the alkoxy groups. Additional precursors may have alkyl groups suchas ethyl, propyl, butyl, pentyl, and/or hexyl groups, in addition to, orin lieu of, one or more methyl groups. Similarly, additional precursorsmay have alkoxy groups such as ethoxy, propoxy, butoxy, pentoxy, and/orhexoxy groups, in addition to, or in lieu of, one or more methoxygroups. Additional embodiments of exemplary deposition precursors mayinclude those having Formula 1:

wherein in Formula 1,R¹ may include a C₁-C₆ alkyl group, such as —CH₃, —CH₂CH₃, —CH₂CH₂CH₃,—CH₂CH₂CH₂CH₃, —CH₂CH₂CH₂CH₂CH₃, or —CH₂CH₂CH₂CH₂CH₂CH₃,R² may include a C₁-C₆ alkyl group, such as —CH₃, —CH₂CH₃, —CH₂CH₂CH₃,—CH₂CH₂CH₂CH₃, —CH₂CH₂CH₂CH₂CH₃, or —CH₂CH₂CH₂CH₂CH₂CH₃,R³ may include —OCH₃, —CH₃, —H, —(CH₂)_(n)CH₃, —O(CH₂)_(n)CH₃, —CH═CH₂,—CH₂—CH₂—(CH₂CH₃)₂, or —CH₂—CH(CH₃)₂, where n=1 to 5, andR⁴ may include —OCH₃, —CH₃, —H, —(CH₂)_(n)CH₃, —O(CH₂)_(n)CH₃, —CH═CH₂,—CH₂—CH₂—(CH₂CH₃)₂, or —CH₂—CH(CH₃)₂, where n=1 to 5.

Embodiments of the present methods include forming a material from aplasma effluent made from one or more deposition precursors described byFormula 1. The material formed may be asilicon-oxygen-and-carbon-containing material, such as carbon-dopedsilicon oxide. Additional examples ofsilicon-oxygen-and-carbon-containing precursors that may be used to forma plasma effluent and deposit the presentsilicon-oxygen-and-carbon-containing materials on a substrate areprovide below. These exemplary precursors may be provided as a singleprecursor, or may be combined as two or more precursors to make thedeposition precursor that forms the plasma effluent:

Although any of the noted precursors may be utilized, in someembodiments the precursors may be characterized by a carbon-to-oxygenratio that is less than or about 4:1, to facilitate higher hardnessvalues. For example, in some embodiments the precursor may becharacterized by a carbon-to-oxygen ratio that is less than or about3:1, less than or about 2:1, less than or about 4:3, or less.Optionally, an additional amount of oxygen may be flowed with thesilicon precursor to further adjust or maintain a ratio of oxygen tocarbon within the film being formed. At operation 310, a plasma may begenerated of the precursors within the processing region, such as byproviding RF power to the faceplate to generate a plasma withinprocessing region 220, although any other processing chamber capable ofproducing plasma may similarly be used. The plasma may be generated atany of the frequencies previously described, and may be generated at afrequency less than 15 MHz (e.g., 13.56 MHz). Although higher frequencymay be used, in some embodiments the lower frequency plasma generationmay facilitate removal of carbon during processing, unlike higher plasmafrequency operations.

As noted above, the plasma effluent may be introduced to a heatedsubstrate to facilitate an as-deposited material with low-k andhigh-hardness. The deposition may be performed at substrate temperaturesgreater than or about 300° C., which may improve release of carbon fromthe film, as well as cross-linking of silicon and oxygen chains withinthe material network. As will be explained further below, while somecarbon aspects may be beneficial to the film, others may be lessbeneficial to the material produced. Accordingly, by increasing thedeposition temperature, film properties may be improved. Consequently,in some embodiments the depositions may occur at substrate temperaturesgreater than or about 350° C., greater than or about 375° C., greaterthan or about 400° C., greater than or about 425° C., greater than orabout 450° C., greater than or about 475° C., greater than or about 500°C., or higher. Particularly for precursors characterized by reducedcarbon incorporation relative to oxygen incorporation, highertemperature may facilitate breaking weaker Si—C—Si bonds relative tosilicon-and-oxygen bonding, which may reduce carbon incorporation withinthe film and provide increased hardness over conventional films. Asexplained below, this may be controlled to maintain an amount of carbonincorporation to maintain a lower dielectric constant for the film.

Material formed in the plasma may be deposited on the substrate atoperation 315, which may produce a silicon-oxygen-and-carbon-containingmaterial. In some embodiments the deposition rate may exceed 500 Å/min,and may be deposited at a rate greater than or about 700 Å/min, greaterthan or about 1,000 Å/min, greater than or about 1,200 Å/min, greaterthan or about 1,400 Å/min, greater than or about 1,600 Å/min, greaterthan or about 1,800 Å/min, greater than or about 2,000 Å/min. Afterdeposition to a sufficient thickness, many conventional processes maythen transfer the substrate to a second chamber to perform a treatment,such as a UV treatment or other post-deposition treatment. This mayreduce throughput, and may increase production costs by requiring anadditional chamber or tool to perform the treatment. The presenttechnology, however, may produce materials, including carbon-dopedsilicon oxide, which may be characterized by sufficient materialproperties as deposited, and without additional treatments, such as a UVtreatment. Although embodiments of the present technology may encompassadditional treatments subsequent deposition, the as-depositedcharacteristics of the film may include a range of improvements overconventional technology.

As explained above, conventional technologies operating at lower plasmafrequencies may cause an amount of ion bombardment that may otherwiserelease carbon-containing materials from the deposited materials, whichmay increase the dielectric constant of the film. By utilizing higherplasma frequencies, along with precursors according to the presenttechnology, low-k dielectric materials may be produced that may becharacterized by a dielectric constant of less than or about 3.5, andmay be less than or about 3.45, less than or about 3.4, less than orabout 3.35, less than or about 3.3, less than or about 3.25, less thanor about 3.2, less than or about 3.15, less than or about 3.1, less thanor about 3.05, less than or about 3.0, or less.

Dielectric constant may be related to material properties of thematerial, where the lower the dielectric constant (i.e., k-value), thelower the Young's modulus and/or hardness of the as-deposited material.By producing silicon-oxygen-and-carbon-containing materials according toembodiments of the present technology, hardness and modulus of theas-deposited low-k material may be higher than would otherwise occurwith conventional PECVD deposition methods. For example, in someembodiments, the present technology may produce materials characterizedby a Young's modulus of greater than or about 5.0 Gpa, and may becharacterized by a Young's modulus of greater than or about 5.5 Gpa,greater than or about 6.0 Gpa, greater than or about 6.5 Gpa, greaterthan or about 7.0 Gpa, greater than or about 7.5 Gpa, greater than orabout 8.0 Gpa, greater than or about 8.5 Gpa, greater than or about 9.0Gpa, greater than or about 9.5 Gpa, greater than or about 10.0 Gpa, orhigher. Similarly, the present technology may produce materialscharacterized by a hardness of greater than or about 3 Gpa, and may becharacterized by a hardness of greater than or about 3.5 Gpa, greaterthan or about 4 Gpa, greater than or about 4.5 Gpa, greater than orabout 5 Gpa, greater than or about 5.5 Gpa, greater than or about 6 Gpa,greater than or about 6.5 Gpa, greater than or about 7 Gpa, greater thanor about 7.5 Gpa, greater than or about 8 Gpa, greater than or about 10Gpa, or higher. Consequently, the present technology may producesilicon-oxygen-and-carbon-containing material characterized by a lowdielectric constant and high modulus and hardness characteristics.

The material characteristics produced by embodiments of the presenttechnology may be related to an amount of methyl groups incorporatedinto the film, as well as an amount of non-methyl carbon incorporatedwithin the film, such as CH₂ or CH, bonded within the material. Theprocessing may release an amount of these materials. For example, insome embodiments, as-deposited materials produced according to thepresent technology may be characterized by a methyl or CH₃ percentageincorporated or retained within the material of greater than or about1%, which may impact both dielectric constant as well as hardness, andmay facilitate increased hardness. Accordingly, in some embodiments theas-deposited film may be characterized by a methyl incorporation withinthe film of greater than or about 1.25%, greater than or about 1.5%,greater than or about 1.75%, greater than or about 1.85%, greater thanor about 1.95%, greater than or about 2%, greater than or about 2.1%,greater than or about 2.2%, greater than or about 2.25%, greater than orabout 2.5%, greater than or about 3%, greater than or about 3.5%, orhigher.

Additionally, a percentage of SiCSi may be less than or about 1% in theas-deposited materials, and may be less than or about 0.9%, less than orabout 0.8%, less than or about 0.7%, less than or about 0.6%, less thanor about 0.5%, less than or about 0.4%, less than or about 0.3%, lessthan or about 0.2%, less than or about 0.1%, less than or about 0.075%,less than or about 0.05%, less than or about 0.025%, or less, which mayhelp reduce the dielectric constant relative to the hardness. However,by maintaining an amount of SiCSi bonding, dielectric constant may belowered while hardness is increased, and accordingly in some embodimentsthe SiCSi percentage may be maintained greater than or about 0.1% andmay be maintained greater than or about 0.15%, or higher. By utilizingsilicon-oxygen-and-carbon-containing precursors and the processingcharacteristics with higher oxygen-incorporation relative to carbonincorporation according to embodiments of the present technology, low-kdielectric materials may be produced, which may be characterized byincreased hardness and Young's modulus values, among other materialproperties.

In the preceding description, for the purposes of explanation, numerousdetails have been set forth in order to provide an understanding ofvarious embodiments of the present technology. It will be apparent toone skilled in the art, however, that certain embodiments may bepracticed without some of these details, or with additional details.

Having disclosed several embodiments, it will be recognized by those ofskill in the art that various modifications, alternative constructions,and equivalents may be used without departing from the spirit of theembodiments. Additionally, a number of well-known processes and elementshave not been described in order to avoid unnecessarily obscuring thepresent technology. Accordingly, the above description should not betaken as limiting the scope of the technology.

Where a range of values is provided, it is understood that eachintervening value, to the smallest fraction of the unit of the lowerlimit, unless the context clearly dictates otherwise, between the upperand lower limits of that range is also specifically disclosed. Anynarrower range between any stated values or unstated intervening valuesin a stated range and any other stated or intervening value in thatstated range is encompassed. The upper and lower limits of those smallerranges may independently be included or excluded in the range, and eachrange where either, neither, or both limits are included in the smallerranges is also encompassed within the technology, subject to anyspecifically excluded limit in the stated range. Where the stated rangeincludes one or both of the limits, ranges excluding either or both ofthose included limits are also included.

As used herein and in the appended claims, the singular forms “a”, “an”,and “the” include plural references unless the context clearly dictatesotherwise. Thus, for example, reference to “a material” includes aplurality of such materials, and reference to “the precursor” includesreference to one or more precursors and equivalents thereof known tothose skilled in the art, and so forth.

Also, the words “comprise(s)”, “comprising”, “contain(s)”, “containing”,“include(s)”, and “including”, when used in this specification and inthe following claims, are intended to specify the presence of statedfeatures, integers, components, or operations, but they do not precludethe presence or addition of one or more other features, integers,components, operations, acts, or groups.

1. A method of forming a silicon-and-carbon-containing material, themethod comprising: flowing a silicon-oxygen-and-carbon-containingprecursor into a processing region of a semiconductor processingchamber, wherein a substrate is housed within the processing region ofthe semiconductor processing chamber; forming a plasma within theprocessing region of the silicon-oxygen-and-carbon-containing precursor,wherein the plasma is formed at a frequency below 15 MHz; and depositinga silicon-and-carbon-containing material on the substrate, wherein thesilicon-and-carbon-containing material as-deposited is characterized bya dielectric constant below or about 3.5.
 2. The method of forming asilicon-and-carbon-containing material of claim 1, wherein the methodfurther comprises flowing oxygen (O₂) gas into the processing region ofthe semiconductor processing chamber.
 3. The method of forming asilicon-and-carbon-containing material of claim 1, wherein thesilicon-and-carbon-containing material as-deposited is characterized bya hardness of greater than or about 3 Gpa.
 4. The method of forming asilicon-and-carbon-containing material of claim 1, wherein the plasma isformed at a frequency of about 13.56 MHz.
 5. The method of forming asilicon-and-carbon-containing material of claim 1, wherein thesilicon-and-carbon-containing material as-deposited is characterized bya dielectric constant ranging from about 3.1 to about 3.3.
 6. The methodof forming a silicon-and-carbon-containing material of claim 1, whereinthe silicon-and-carbon-containing material as-deposited is characterizedby a hardness of greater than or about 5 Gpa.
 7. The method of forming asilicon-and-carbon-containing material of claim 1, wherein thesilicon-and-carbon-containing material as-deposited is characterized bya Young's modulus of greater than or about 5 Gpa.
 8. The method offorming a silicon-and-carbon-containing material of claim 1, wherein thesilicon-and-carbon-containing material as-deposited is characterized bya methyl incorporation less than or about 2.5%.
 9. The method of forminga silicon-and-carbon-containing material of claim 1, wherein thesilicon-and-carbon-containing material as-deposited is characterized bya Si—C—Si bond incorporation less than or about 0.5%.
 10. A method offorming a silicon-and-carbon-containing material, the method comprising:providing a deposition precursor into a processing region of asemiconductor processing chamber, wherein a substrate is housed withinthe processing region of the semiconductor processing chamber, andwherein the deposition precursor is characterized by Formula 1:

wherein R¹ may include a C₁-C₆ alkyl group, such as —CH₃, —CH₂CH₃,—CH₂CH₂CH₃, —CH₂CH₂CH₂CH₃, —CH₂CH₂CH₂CH₂CH₃, or —CH₂CH₂CH₂CH₂CH₂CH₃, R²may include a C₁-C₆ alkyl group, such as —CH₃, —CH₂CH₃, —CH₂CH₂CH₃,—CH₂CH₂CH₂CH₃, —CH₂CH₂CH₂CH₂CH₃, or —CH₂CH₂CH₂CH₂CH₂CH₃, R³ may include—OCH₃, —CH₃, —H, —(CH₂)_(n)CH₃, —O(CH₂)_(n)CH₃, —CH═CH₂,—CH₂—CH₂—(CH₂CH₃)₂, or —CH₂—CH(CH₃)₂, and R⁴ may include —OCH₃, —CH₃,—H, —(CH₂)_(n)CH₃, —O(CH₂)_(n)CH₃, —CH═CH₂, —CH₂—CH₂—(CH₂CH₃)₂, or—CH₂—CH(CH₃)₂; forming a plasma within the processing region of thedeposition precursor, wherein the plasma is formed at a frequency lessthan 15 MHz; and depositing a silicon-and-carbon-containing material onthe substrate, wherein the silicon-and-carbon-containing materialas-deposited is characterized by a dielectric constant below or about3.5.
 11. The method of forming a silicon-and-carbon-containing materialof claim 10, wherein the method further comprises providing oxygen (O₂)gas into the processing region of the semiconductor processing chamberwith the deposition precursor.
 12. The method of forming asilicon-and-carbon-containing material of claim 10, wherein thedeposition precursor is characterized by ratio of oxygen to silicon ofgreater than or about
 2. 13. The method of forming asilicon-and-carbon-containing material of claim 10, wherein thesilicon-and-carbon-containing material as-deposited is characterized bya dielectric constant ranging from about 3.1 to about 3.3.
 14. Themethod of forming a silicon-and-carbon-containing material of claim 10,wherein the silicon-and-carbon-containing material as-deposited ischaracterized by a hardness of greater than or about 3 Gpa.
 15. Themethod of forming a silicon-and-carbon-containing material of claim 10,wherein the silicon-and-carbon-containing material as-deposited ischaracterized by a Young's modulus of greater than or about 5 Gpa. 16.The method of forming a silicon-and-carbon-containing material of claim10, wherein the silicon-and-carbon-containing material as-deposited ischaracterized by a methyl incorporation less than or about 2.5%.
 17. Themethod of forming a silicon-and-carbon-containing material of claim 10,wherein the silicon-and-carbon-containing material as-deposited ischaracterized by a Si—C—Si bond incorporation less than or about 0.5%.18. A method of forming a silicon-and-carbon-containing material, themethod comprising: flowing a silicon-oxygen-and-carbon-containingprecursor into a processing region of a semiconductor processingchamber, wherein a substrate is housed within the processing region ofthe semiconductor processing chamber; forming a plasma within theprocessing region of the silicon-oxygen-and-carbon-containing precursor,wherein the plasma is formed at a frequency less of about 13.56 MHz; anddepositing a silicon-and-carbon-containing material on the substrate,wherein the silicon-and-carbon-containing material as-deposited ischaracterized by a dielectric constant below or about 3.5 and a hardnessof greater than about 3 Gpa.
 19. The method of forming asilicon-and-carbon-containing material of claim 18, wherein thesilicon-and-carbon-containing material as-deposited is characterized bya Young's modulus of greater than or about 5 Gpa.
 20. The method offorming a silicon-and-carbon-containing material of claim 18, whereinthe silicon-and-carbon-containing material as-deposited is characterizedby a Si—C—Si bond incorporation less than or about 0.5%.